Prison cotton plantation.

What would happen if a prison started using it's inmates to pick cotton in the plantations, brought them there in the early hours of the morning in handcuffs, whipped the backs of those that didn't work hard enough and hauled their asses back to their cells after a hard day's labour.

Seriously, would anyone notice?

Then the government has an incentive to jail people for profit.
They already do something like this in the states, paying convicts below minimum wage to work, and using early release as an incentive to cooperate.

Also, chain gangs.